Power transmission

ABSTRACT

A fluid pressure energy translating device of the sliding vane type having a stator with high and low pressure passages and a vane track with a vane carrying rotor rotatably mounted therein and encased between a pair of cheek plates; one of said cheek plates having a bearing mounted therein and extending therefrom into abutment with said vane carrying rotor and means for resiliently biasing said rotor towards said bearing means thereby defining a clearance space between the rotor and each of said cheek plates.

United States Patent w13,ss2,241

Inventors Albin J. Niemiec Sterling Heights; Raymond B. Pettibone, Detroit, both of, Mich. A pl. No. 808,194 Filed Mar. 18, 1969 Patented June 1, 1971 Assignee Sperry Rand Corporation Troy, Mich.

POWER TRANSMISSION 12 Claims, 3 Drawing Figs.

U.S.Cl 418/107, 91/80 Int. Cl F04c 17/00, F01c 21/10 Field of Search 103/136,

[56] References Cited UNlTED STATES PATENTS 1,972,565 9/1934 Kempton 418/107 3,349,757 10/1967 Artajo 418/107 3,204,565 /1965 Kirkpatrick 103/136 3,012,511 12/1961 Adams 103/136 3,070,032 12/1962 Rohde 103/136 2,491,100 12/1949 Frei 230/152 Primary Examiner-Henry F. Raduazo Attorney-Van Meter and George ABSTRACT: A fluid pressure energy translating device of the sliding vane type having a stator with high and low pressure passages and a vane track with a vane carrying rotor rotatably mounted therein and encased between a pair of cheek plates; one of said cheek plates having a bearing mounted therein and extending therefrom into abutment with said vane carrying rotor and means for resiliently biasing said rotor towards said bearing means thereby defining a clearance space between the rotor and each of said cheek plates.

rlQ I memes JUN 1 197i Hrl l 3582.241 SHEET 1 OF 2 BY RAYMOND B. PETTIBONE ATTORNEYS PATENTEDJUN H911 3.582.241

' sum 2 [IF 2 FIG. 2

, INVENTUR. ALBIN J. NIEMIEC BY RAYMOND 8. PE TTIBONE ATTORNEYS POWER TRANSMISSION BACKGROUND OF THE INVENTION This invention relates to power transmissions and is particularly applicable to those of the type comprising-two or more fluid pressure energy translating devices, one of which can function as a pump and the other as a fluid motor, and particularly, this invention relates to an improvement in sliding vane type pumps and motors.

Units of this type generally comprise a stator including a vane cam track within which is rotatably mounted a rotor carrying radially sliding vanes to form fluid inlet and fluid outlet ports between the periphery of the rotor and the vane track, either of which may be a low pressure or a high pressureworking zone, depending upon the pump or motor function of the device.

In such devices, the rotor is encased between a pair of check plates which provide a means for directing fluid pressure to and from the pressure working zones. A certain predetermined clearance is provided between the rotor and each cheek plate for the purpose of connecting the fluid working zones to the drive shaft area or low pressure zone. Thus, not only is fluid provided for lubricating the drive shaft bearing, but a fluid film is created between the rotor and each cheek plate.

At high speed and pressure operation,.there is a notable pressure drop across each face of the rotor which produces an internal leakage.

The predetermined clearance between the rotor and the cheek plates is designed such that the leakage thereacross will be sufficient to provide an acceptable fluid film for lubricating and cooling purposes, but without significantly impairing the volumetric efflciency of the device; If a rotor which is initially centered between the two cheek plates shifts so as to approach contact with one of the cheek plates, the leakage path between the opposite rotor face and the cheek plate will be twice as great, and since the leakage rate will vary by thecube of the distance between the rotor and cheek .plate, the rate of leakage between the opposite rotor face and cheek plate will approach a value approximately eight times greater than when the rotor was centrally positioned between the two plates with the net effect that the system leakage is substantially increased.

It would thus be very desirable to provide a fluid device of the type described in which the rotor is centrally located between the two cheek plates during all phases of operation and one which will not only center the rotor, but will maintain design clearances regardless of changes in temperature of the device over a-wide range.

SUMMARY OF THE INVENTION This invention comprises a rotary fluid pressure energy translating device having a pumping mechanism carried by a shaft rotatably mounted in said device, said pumping mechanism being mounted between two cheek plates, one of said cheek plates having a bearing means extending therefrom and in abutment with said pumping mechanism, and means opposite said cheek platefor biasing said pumping mechanism toward said bearing means.

It is therefore an object of this invention to provide an improved, efficient, and long wearing fluid pressure energy translating device of the sliding vane type.

It is also an object of this invention to provide such a device having an improved rotor cheek plate construction, which will reduce noise and wear between the same.

It is a further object of this invention to provide such a device which is capable of both high pressure and high speed operation without an excessive amount of leakage between 1 the rotor and its associated cheek plates.

It is still another object of this invention to provide a device *whieh is capable of operating over a wide range of tempera- .atures by compensating for the same.

It is still another object of this invention to provide a device of the type described having all the advantages previously recited without substantially increasing the overall dimensions or cost of the devices currently in production.

Further objects and advantages of the present invention will be apparent from the following description, reference being made to the accompanying drawing wherein a preferred form of the present invention is clearly shown.

IN THE DRAWING FIG. 1 is a longitudinal sectional view of a fluid pressure energy translating device embodying a preferred form of the present invention and taken on line I-l of FIG. 2.

FIG. 2 is a partially sectioned side view of the left side of FIG. I.

FIG. 3 is an enlarged, partially sectioned view showing the rotor clearance and centering mechanism illustrated in FIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to the several figures, there is shown a presently preferred, but merely illustrative embodiment of the inventive principles, a pump 10 of the sliding vane type. The housing I2 of the pump 10 comprises a body member 14 and an end cover 16 which are secured to each other by means of boltsl8 extending through the body 14 and into threaded holes provided in the cover 16. The body member 14 is provided-with an inlet supply connection 20 having an operating passage leadingv therefrom and divided into two branch passages, one of which is indicated at 22. Said passages extending in opposite directions and each branch terminating in a fluid inlet port, one of which is indicated at 24, provided in a pressure plateor cheek plate 26.

The housing-l2 has cylindrical bore 28 in which is floatably mounted a cartridge unit 30. The cartridge '30 is comprised of a cam ring 32, a pumping mechanism or rotor 34 which is rotatable in the cam ring 32 and a pair of check plates 26 and 36positioned on each side of the rotor 34 and ring 32. A plurality of vanes'38 are movable in and out of slots 40 provided in the rotor 34. The cam ring 32 is designed in such a manner that it has a width which is greater than the rotor 34 positioned therein. The outer periphery of the inner faces 42 and 44 respectively of thecheek plates 26 and 36 abut the opposite sides of the cam ring 32 thereby providing a small running clearance between the plates 26 and 36 and the associated faces on the side surface of the rotor 34. A pair of bolts extend through the plates 26 and 36 and ring 32, one of which is shown at 46. The-bolts 46 extend through plate 36 and are secured together by means of nuts not shown. The nut and bolt assembly hold the ring 32, rotor 34, and plates 26 and 36 together as a cartridge unit for assembly convenience as well .as to prevent radial rotation of the plates 26 and 36 within the bore 28. The nuts are usually loosely fitted on the bolts 46 and have no effect on mechanically loading the bolts. Thus, the cheek plates and cartridge are considered to be floatably mounted within the bore 28.

The rotor 34 is driven by a shaft 48 rotatably mounted within the cover 16 by means of a bearing 50 located near one end of the bore 28 and a bearing 52 located within the body 14 at the other end of the bore 28. The shaft 48 is operatively connected to the rotor by means of a splined connection indicated by the numeral 54 and is further provided with a shaft seal at 56 which prevents leakage at the juncture of the shaft 48 and the cover 16.

A stepped portion 58 on the outer face of plate 26 is provided and forms an internal annular hub member 60. The cartridge unit 30 defines with the housing 12 and with the right end of bore 28 an operating pressure chamber 62 which is connected to the outlet side of the pump 10. The pressure chamber 62 acts against the annular space of the outer rim starting at the outer periphery of the plate 26 and extending inwardly with the hub 60 so as to urge the pressure plate 26- into fluid sealing engagement with the outer surface of the rotor 34, and against the cam ring 32 forcing the entire cartridge including the pressure plate 36 against the left end portion of the bore 28, thus providing axial stability for the unit. Thus, the cheek plates 26 and 36 respectively abut the cam ring side surfaces 64 and 66 in a generally annular region located near the periphery of each plate.

A pair of low pressure chambers 68 and 70 are located one on each end of the bore 28 and are connected to the inlet side of the pump.l0. The low pressure chamber 68 is formed by the i hub member 66 with the bearing surface directly opposite therefrom. The low pressure chamber 68 has a circumferential surface 72 in the cover 16 in which the stepped up portion 58 of the floating pressure plate 26 is telescopically engaged.

The contour of the inner surface of the cam ring 32 forms a vane track substantially elliptical in shape and is indicated by the numeral 74 which, together with the outer periphery of the rotor and the adjoining surfaces of the cheek plates define two opposed working chambers indicated by the numerals 76 and 78, each of which for the purposes of convenience, may be divided into fluid inlet and fluid outlet zones and which forms a sliding vane device of the double throw type. The fluid inlet zones comprise those portions of the working chambers 76 and 78 respectively registering with the fluid inlet port openings at 24.

The fluid delivery zones comprise those portions of the working chambers 76 and 78 registering respectively with opposed arcuately shaped fluid delivery port openings one of which is shown at 80, which are recessed in the surfaces of the pressure plates 26 and 36 and which are directly connected to the pressure chamber 62 by means of passageways 82 leading therefrom, one of which is shown in FIG. 1. An outlet connection port 84 is provided in the end cover 16 and directly communicates with the outlet pressure chamber 62 fomied in the enlarged bore 28 wherein the pressure plate 26 is floatably mounted.

The radial slots 40 in the rotor are formed by parallel walls which guide the vanes as they move radially inward and outward and also an enlarged pressure chamber at the inner end of each slot and is indicated by the numeral 36. Spacing between each pair of vanes is adapted to span the distance between each pair of ports in a manner to provide proper sealing between the inlet and outlet porting connected to the inlet and outlet portions of the device. A reaction member for each Jane is indicated by the numeral 88 which, together with a correlated porting arrangement provides a controlled unbalance during the various phases of the device for insuring complete extension of the vanes and also for maintenance of the outer edges of the vanes in contact with the vane track throughout a complete rotary cycle of the device. This type of vane arrangement is well known in the art, and reference may be had to the patent to Duncan B. Gardiner, US. Pat. No. 2,967,488 for a description and explanation of the operation of such a vane.

A pin 90 extends from the body 14 through the cheek plate 36, the ring 32 and into the cheek plate 26 for the purpose of providing proper angular alignment during assembly. A plurality of rings 92 and 94 are provided at strategic locations within the housing 12 so as to prevent leakage between adjacent pressure chambers.

Within the pressure plate 26 there is famed a passageway 96 which extends to the surface of the cheek plate 26 and provides fluid communication during predetermined intervals under the vane within the recess 86. By means of a separate passageway 98 located within the face of the cheek plate 26, fluid at low pressure is supplied to the drive shaft spline and by means of the clearance space between the drive shaft and the bores extending through the cheek plates and the rotor lubricant is provided to the hereinbefore mentioned bearings.

As hereinbefore mentioned, the hydraulic pressure in the chamber 62 acts against a portion of the outer face of cheek plate 26 urging the opposite face thereof into a fluid sealing engagement and mechanical abutment respectively with the rotor 34 and cam ring 32 which, in turn, is forced into abutment with the outer edges of the cheek plate 36, which, in turn, is maintained in axial abutment with the left hand wall of the bore 28 within the housing 12. As shown, in an exaggerated form in FIG. 3, the cam ring 22 is of slightly greater width than the rotor 34 so as to provide the hereinbefore mentioned proper running clearance between the inner faces of the cheek plates and the opposite side surfaces of the rotor. The actual clearance between the corresponding faces is in the order of .OOi of an inch.

Referring now to the FIG. 3 wherein there is shown a more detailed illustration of the subject invention, the drive shaft 48 extends through the rotor 34 and the two cheek plates on opposite sides thereof. The shaft 43 is mounted within the journal bearing 52 which, in turn, is secured within the cheek plate 36 by any suitable means. Along the inner periphery 100 of the cheek piate 36, there is provided an annular recess 102 which is adapted to receive and maintain in place the outer ring 104 of a needle bearing 166. Around the outer periphery of the shaft there is provided a sleeve 108 on which is secured the inner ring 110 of the above mentioned needle bearing. As illustrated, a needle bearing is provided between the inner and outer rings of the bearing for the purpose of allowing relative rotary movement of the two rings. However, any type of ball means may be utilized, such as a ball bearing or the like. it can readily be seen that as the drive shaft moves, the inner ring 110 wili be carried thereby, whereas, the outer ring of the bearing will be in a stationary position within the recess 102. The bearing is of such a design that it extends out beyond the face of the cheek plate 36 by a predetermined amount, and, is adapted to be in abutment with the rotor and will rotate therewith as the same is carried by the shaft at the splined connection 54. The extension of the hearing from the face of the cheek plate will prevent contact between the cheek plate 36- and the rotor by the amount of extension irrespective of the pressures operating on the opposite side of the rotor. Any desired amount will be dependent upon the amount of desired leakage between the two adjacent faces the particular pressure at which the unit will be functioning and the temperature and type of fluid utilized in a particular application. It is desirable that this clearance and thereby the amount of extension of the bearing beyond the face of the cheek plate be equal to one half the distance between the width of the cam ring 32 and the rotor 34.

In order to insure that a proper clearance is maintained on the opposite side of the rotor between the same and the cheek plate 26, a biasing means is provided to urge the rotor leftwardly into abutrnent with the bearing and as illustrated, the biasing means is carried by the shaft and rotatable therewith whereby there is no relative movement between the biasing means, the shaft, the rotor, and the inner ring of the bearing. The biasing means is provided by means of a coil type spring 112 which is disposed between a sleeve 114 about the periphery of the shaft at a point 116 and the face 158 of the rotor. It can very easily be seen that the spring exerts a force on the rotor tending to shift it toward the bearing. When the rotor is in abutment with the bearing, a clearance will exist between the cheek plate 36 and the rotor face thereby preventing contact between the same. If a clearance between the cheek plate 36 and the rotor side is equal to one-half that of the distance between the width of the cam track and the rotor, then a comparable distance or clearance will be maintained between the opposite side 118 of the rotor and cheek plate 26.

Generally, in devices of the type described, there is a fairly constant pressure balance on opposite sides of the pressure rotor. Therefore, when the pressure is disturbed and the rotor is shifted toward the cheek plate the force exerted on the rotor is not of a substantially great magnitude, however, it is high enough to cause damage to the contacting surfaces because of the substantial relative speed between the two parts, and, second, when contact is made on one side, there is a substantial increase in the amount of leakage flowing between the opposite side and the associated cheek plate as hereinbefore mentioned. However, in the instant design, the relatively low resultant force acting on the rotor can be overcome by a spring which has a relatively low spring rate. Therefore, a relatively light coil type spring may be utilized. it should be further noted that both the bearing and the spring circumscribe the shaft 48, and are carried in the manner hereinbefore described.

At the same time that the spring and bearing combination maintain the rotor in a central position relative to its associated cheek plates, the spring will compensate for changes in temperature. For example, after some continuous use, the unit and the fluid therein will warm up with the resultant effect that the change in temperature will cause internal components to expand, such as the rotor and bearing 106. Any such expansion will be adjusted for by a contraction of the spring 112.

It can thus be seen that the present invention has provided an improved, efficient and long wearing pressure energy trans lating device of the sliding vane type and which has an improved rotor cheek plate construction which reduces noise and wear between the same by means of maintaining the rotor centrally positioned between its adjacent cheek plates; and, the same has been accomplished this while providing a means for compensating for changes in temperature in the device which would have had an adverse effect upon the position of the rotor relative to its adjacent cheek plates.

While the form of embodiment of the present invention as herein disclosed constitutes a preferred form, it is to be understood that other forms might be adopted, all coming within the scope of the claims which follow.

What we claim as new and desire to secure by Letters Patent of the United States is:

l. A hydraulic pressure energy translating device comprising: a housing having low and high pressure operating passages, one of which is an inlet passage and the other an outlet passage; a cam track in said housing; a pumping mechanism rotatably mounted within said cam track for pumping fluid from said inlet passage to said outlet passage; said cam track circumscribing said pumping mechanism and having a width greater than said pumping mechanism; means forming a pair of cheek plates on opposite sides of said pumping mechanism, one of said check plates facing one side of said pumping mechanism and being in mechanical abutment with one side of said cam track, while the other and opposite cheek plate faces the other and opposite side of said pumping mechanism and being in mechanical abutment with the other and opposite side of said cam track; bearing means extending from said one cheek plate by a predetermined amount; said bearing means abutting said one pumping mechanism side thereby defining a clearance space between said one cheek plate and said one pumping mechanism side, means engaging said pumping mechanism and biasing the pumping mechanism toward said bearing means, thereby defining a clearance space between said other cheek plate and said other pumping mechanism side whereby contact between the cheek plates and their associated pumping mechanism sides is prevented.

2. A pressure energy translating device as described in claim 1 wherein said biasing means is resilient.

3. A pressure energy translating device as described in claim I wherein said pumping mechanism and said biasing means are carried by a shaft.

4. A pressure energy translating device as described in claim 1 wherein said bearing means comprises an outer ring carried by said one cheek plate; an inner ring, said inner ring extending from said check plate into abutment with said pumping mechanism and ball means disposed between said rings to permit relative rotary movement of said rings.

5. A pressure energy translating device as described in claim 1 wherein said pumping mechanism is carried by a shaft rotatably mounted in said housing; and said bearing means comprise an outer and an inner ring circumscribing said shaft, said outer ring being carried by said one cheek plate, said inner ring being carried by said shaft and movable therewith and extendin from said check plate into abutment with said pumping mec anism; and ball means disposed between said rings to permit relative rotary movement of said rings.

6. A pressure energy translating device as described in claim 5 wherein said one cheek plate has a bore formed therein for receiving a portion of said shaft; and an annular recess formed on the inner periphery of said check plate, said outer ring being carried therein.

7. A pressure energy translating device as described in claim 3 wherein said biasing means is resilient.

8. A pressure energy translating device as described in claim 3 wherein said biasing means comprises a mechanical spring circumscribing said shaft and movable therewith, one end of said spring being in abutment with a portion of said shaft, the other end of said spring being in abutment with said other pumping mechanism side, exerting a force against said pumping mechanism to bias the same against the bearing means.

9. A pressure energy translating device as described in claim 3 wherein said mechanical spring is of a light coil type.

10. A pressure energy translating device as described in claim 8 wherein said bearing means comprises an outer and an inner ring circumscribing said shaft said outer ring being carried by said one cheek plate, said inner ring being carried by said shaft and movable therewith and extending from said cheek plate into abutment with said pumping mechanism; and ball means disposed between said rings to permit relative rotary movement of said rings.

ll. A pressure energy translating device as described in claim 10 wherein said one cheek plate has a bore formed therein for receiving a portion of said shaft; and an annular recess formed on the inner periphery of said cheek plate said outer bearing ring being carried therein.

12. A pressure energy translating device as described in claim 11 wherein said pumping mechanism comprises a vane carrying rotor, said rotor being circumscribed by said cam track, said cam track being of greater width than said rotor. 

1. A hydraulic pressure energy translating device comprising: a housing having low and high pressure operating passages, one of which is an inlet passage and the other an outlet passage; a cam track in said housing; a pumping mechanism rotatably mounted within said cam track for pumping fluid from said inlet passage to said outlet passage; said cam track circumscribing said pumping mechanism and having a width greater than said pumping mechanism; means forming a pair of cheek plates on opposite sides of said pumping mechanism, one of said cheek plates facing one side of said pumping mechanism and being in mechanical abutment with one side of said cam track, while the other and opposite cheek plate faces the other and opposite side of saId pumping mechanism and being in mechanical abutment with the other and opposite side of said cam track; bearing means extending from said one cheek plate by a predetermined amount; said bearing means abutting said one pumping mechanism side thereby defining a clearance space between said one cheek plate and said one pumping mechanism side, means engaging said pumping mechanism and biasing the pumping mechanism toward said bearing means, thereby defining a clearance space between said other cheek plate and said other pumping mechanism side whereby contact between the cheek plates and their associated pumping mechanism sides is prevented.
 2. A pressure energy translating device as described in claim 1 wherein said biasing means is resilient.
 3. A pressure energy translating device as described in claim 1 wherein said pumping mechanism and said biasing means are carried by a shaft.
 4. A pressure energy translating device as described in claim 1 wherein said bearing means comprises an outer ring carried by said one cheek plate; an inner ring, said inner ring extending from said cheek plate into abutment with said pumping mechanism and ball means disposed between said rings to permit relative rotary movement of said rings.
 5. A pressure energy translating device as described in claim 1 wherein said pumping mechanism is carried by a shaft rotatably mounted in said housing; and said bearing means comprise an outer and an inner ring circumscribing said shaft, said outer ring being carried by said one cheek plate, said inner ring being carried by said shaft and movable therewith and extending from said cheek plate into abutment with said pumping mechanism; and ball means disposed between said rings to permit relative rotary movement of said rings.
 6. A pressure energy translating device as described in claim 5 wherein said one cheek plate has a bore formed therein for receiving a portion of said shaft; and an annular recess formed on the inner periphery of said cheek plate, said outer ring being carried therein.
 7. A pressure energy translating device as described in claim 3 wherein said biasing means is resilient.
 8. A pressure energy translating device as described in claim 3 wherein said biasing means comprises a mechanical spring circumscribing said shaft and movable therewith, one end of said spring being in abutment with a portion of said shaft, the other end of said spring being in abutment with said other pumping mechanism side, exerting a force against said pumping mechanism to bias the same against the bearing means.
 9. A pressure energy translating device as described in claim 3 wherein said mechanical spring is of a light coil type.
 10. A pressure energy translating device as described in claim 8 wherein said bearing means comprises an outer and an inner ring circumscribing said shaft said outer ring being carried by said one cheek plate, said inner ring being carried by said shaft and movable therewith and extending from said cheek plate into abutment with said pumping mechanism; and ball means disposed between said rings to permit relative rotary movement of said rings.
 11. A pressure energy translating device as described in claim 10 wherein said one cheek plate has a bore formed therein for receiving a portion of said shaft; and an annular recess formed on the inner periphery of said cheek plate said outer bearing ring being carried therein.
 12. A pressure energy translating device as described in claim 11 wherein said pumping mechanism comprises a vane carrying rotor, said rotor being circumscribed by said cam track, said cam track being of greater width than said rotor. 